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31.
32.
Domier LL Latorre IJ Steinlage TA McCoppin N Hartman GL 《Archives of virology》2003,148(10):1925-1941
Summary. The variability of North American and Asian strains and isolates of Soybean mosaic virus was investigated. First, polymerase chain reaction (PCR) products representing the coat protein (CP)-coding regions of 38 SMVs were analyzed for restriction fragment length polymorphisms (RFLP). Second, the nucleotide and predicted amino acid sequence variability of the P1-coding region of 18 SMVs and the helper component/protease (HC/Pro) and CP-coding regions of 25 SMVs were assessed. The CP nucleotide and predicted amino acid sequences were the most similar and predicted phylogenetic relationships similar to those obtained from RFLP analysis. Neither RFLP nor sequence analyses of the CP-coding regions grouped the SMVs by geographical origin. The P1 and HC/Pro sequences were more variable and separated the North American and Asian SMV isolates into two groups similar to previously reported differences in pathogenic diversity of the two sets of SMV isolates. The P1 region was the most informative of the three regions analyzed. To assess the biological relevance of the sequence differences in the HC/Pro and CP coding regions, the transmissibility of 14 SMV isolates by Aphis glycines was tested. All field isolates of SMV were transmitted efficiently by A. glycines, but the laboratory isolates analyzed were transmitted poorly. The amino acid sequences from most, but not all, of the poorly transmitted isolates contained mutations in the aphid transmission-associated DAG and/or KLSC amino acid sequence motifs of CP and HC/Pro, respectively.Received March 20, 2002; accepted May 14, 2003 相似文献
33.
Yang GC; Croaker D; Zhang AL; Manglick P; Cartmill T; Cass D 《Human molecular genetics》1998,7(6):1047-1052
Lethal white foal syndrome (LWFS) is a congenital anomaly of horses
characterized by a white coat colour and aganglionosis of the bowel, which
is similar to Hirschsprung disease (HSCR). We decided to investigate
possible mutations of the endothelin-B receptor gene ( EDNRB ) in LWFS as
recent studies in mutant rodents and some patients have demonstrated EDNRB
defects. First, we identified a full-length cDNA for horse EDNRB . This
cDNA fragment contained a 1329 bp open reading frame which encoded 443
amino acid residues. The predicted amino acid sequence was 89, 91 and 85%
identical to human, bovine and mouse as well as rat EDNRB respectively, but
only 55% identical to the human, bovine and rat endothelin A receptor
(EDNRA). Secondly, sequence analysis, together with allele-specific PCR and
the amplification- created restriction site (ACRS) technique, revealed a
dinucleotide TC-- >AG mutation, which changed isoleucine to lysine in
the predicted first transmembrane domain of the EDNRB protein. This was
associated with LWFS when homozygous and with the overo phenotype when
heterozygous.
相似文献
34.
35.
Expression of sperm antigens during spermatogenesis and maturation detected with monoclonal antibodies 总被引:1,自引:0,他引:1
H D Moore T D Hartman A C Brown C A Smith D H Ellis 《Experimental and clinical immunogenetics》1985,2(2):84-96
The expression of hamster sperm antigens was investigated during spermatogenesis and sperm maturation with the use of monoclonal antibodies generated in culture from mice immunized with hamster cauda epididymal spermatozoa or sperm heads. Antigens were localized by immunofluorescence and immunoperoxidase techniques which were first visualized on isolated spermatids over the developing acrosome. In one case, antibody inhibited fertilization in vitro although localization on testicular or epididymal spermatozoa was minimal compared with the early spermatid. Antibodies also recognized surface antigens first expressed in the epididymis whose localization on the spermatozoon altered during epididymal transit or incubation in capacitating medium. The results were discussed in relation to the expression and function of surface determinants on the haploid germ cell. 相似文献
36.
Much research has been done to develop the ideal bone graft substitute (BGS). One approach to develop this ideal BGS is the use of growth factors, but for this approach osteoprogenitor cells are needed at the site of reconstruction. An alternative is a cell-based approach, where enough cells are provided to form bone in a carrier material. In previous studies of our group, titanium (Ti) carriers have been used, because of the excellent mechanical properties and the bone-compatibility of this material. On the other hand, calcium phosphate (CaP) ceramics are known for their excellent osteoconductivity. The aim of this study is to investigate the influence of the carrier in a cell-based bone regeneration approach, whereby we hypothesize that CaP-ceramic implants will induce more bone formation than Ti-fiber implants, in the same animal model as our previous experiment. Ti-fiber mesh implants and ceramic implants were seeded with rat bone marrow cells (RBM) and implanted subcutaneously. Histological analysis after one, three and six weeks showed differences in the way of bone formation in the two groups: bone appeared to grow from the center to the periphery of the implant in the titanium group, while bone formation in the ceramic group occurred through the whole implant. Histomorphometrical analysis after one week showed very limited bone formation for both the titanium and ceramic group. At three weeks, the amount of bone formation was increased till about 10% for the titanium group and 18% for the ceramic group. No significant difference between the two groups could be observed. In the six week group, the bone formation was 6% (Ti) and 23% (CaP), respectively (P < 0.001). Further, bone formation started earlier in the CaP-ceramic scaffolds than in the Ti scaffolds. Our hypothesis could be confirmed: ceramic implants induce more bone formation than titanium implants. 相似文献
37.
BDNF increases release probability and the size of a rapidly recycling vesicle pool within rat hippocampal excitatory synapses 总被引:2,自引:1,他引:2
William J. Tyler Xiao-lei Zhang Kenichi Hartman Jochen Winterer Wolfgang Muller Patric K. Stanton Lucas Pozzo-Miller 《The Journal of physiology》2006,574(3):787-803
Exerting its actions pre-, post- and peri-synaptically, brain-derived neurotrophic factor (BDNF) is one of the most potent modulators of hippocampal synaptic function. Here, we examined the effects of BDNF on a rapidly recycling pool (RRP) of vesicles within excitatory synapses. First, we estimated vesicular release in hippocampal cultures by performing FM4-64 imaging in terminals impinging on enhanced green fluorescent protein (eGFP)-labelled dendritic spines – a hallmark of excitatory synapses. Consistent with a modulation of the RRP, BDNF increased the evoked destaining rate of FM4-64 only during the initial phase of field stimulation. Multiphoton microscopy in acute hippocampal slices confirmed these observations by selectively imaging the RRP, which was loaded with FM1-43 by hyperosmotic shock. Slices exposed to BDNF showed an increase in the evoked and spontaneous rates of FM1-43 destaining from terminals in CA1 stratum radiatum, mostly representing excitatory terminals of Schaffer collaterals. Variance-mean analysis of evoked EPSCs in CA1 pyramidal neurons further confirmed that release probability is increased in BDNF-treated slices, without changes in the number of independent release sites or average postsynaptic quantal amplitude. Because BDNF was absent during dye loading, imaging, destaining and whole-cell recordings, these results demonstrate that BDNF induces a long-lasting enhancement in the probability of transmitter release at hippocampal excitatory synapses by modulating the RRP. Since the endogenous BDNF scavenger TrkB-IgG prevented the enhancement of FM1-43 destaining rate caused by induction of long-term potentiation in acute hippocampal slices, the modulation of a rapidly recycling vesicle pool may underlie the role of BDNF in hippocampal long-term synaptic plasticity. 相似文献
38.
Debelenko LV; Brambilla E; Agarwal SK; Swalwell JI; Kester MB; Lubensky IA; Zhuang Z; Guru SC; Manickam P; Olufemi SE; Chandrasekharappa SC; Crabtree JS; Kim YS; Heppner C; Burns AL; Spiegel AM; Marx SJ; Liotta LA; Collins FS; Travis WD; Emmert-Buck MR 《Human molecular genetics》1997,6(13):2285-2290
Lung carcinoids occur sporadically and rarely in association with multiple
endocrine neoplasia type 1 (MEN1). There are no well defined genetic
abnormalities known to occur in these tumors. We studied 11 sporadic lung
carcinoids for loss of heterozygosity (LOH) at the locus of the MEN1 gene
on chromosome 11q13, and for mutations of the MEN1 gene using dideoxy
fingerprinting. Additionally, a lung carcinoid from a MEN1 patient was
studied. In four of 11 (36%) sporadic tumors, both copies of the MEN1 gene
were inactivated. All four tumors showed the presence of a MEN1 gene
mutation and loss of the other allele. Observed mutations included a 1 bp
insertion, a 1 bp deletion, a 13 bp deletion and a single nucleotide
substitution affecting a donor splice site. Each mutation predicts
truncation or potentially complete loss of menin. The remaining seven
tumors showed neither the presence of a MEN1 gene mutation nor 11q13 LOH.
The tumor from the MEN1 patient showed LOH at chromosome 11q13 and a
complex germline MEN1 gene mutation. The data implicate the MEN1 gene in
the pathogenesis of sporadic lung carcinoids, representing the first
defined genetic alteration in these tumors.
相似文献
39.
D F Middendorf L A Hebert R A Zager J Hartman D Bitzel 《The Journal of laboratory and clinical medicine》1986,108(6):577-580
The urine urea nitrogen/urine creatinine excretion ratio (UUN/UCr) of a "spot" urine specimen obtained approximately 5 hours after the last meal of the day can be used to accurately calculate the urinary urea excretion for the previous 24-hour period. Because UUN excretion is largely determined by dietary intake of protein nitrogen, this method can be used to estimate dietary protein intake for the previous 24-hour period. Strategies for using this simple method for inexpensively and continuously monitoring dietary protein intake are discussed. 相似文献
40.
Ladislav Pila Lucie Kvasni
kov Stanislavsk Roman Kvasni
ka Richard Hartman Ivana Tich 《Nutrients》2021,13(6)
Social media platforms have become part of many people’s lives. Users are spending more and more time on these platforms, creating an active and passive digital footprint through their interaction. This footprint has high research potential in many research areas because understanding people’s communication on social media is essential in understanding their values, attitudes, experiences and behaviors. Researchers found that the use of social networking sites impacts adolescents’ eating behavior. If we define adolescents as individuals between ages 10 and 24 (WHO’s definition), 76% of USA young people at age 18–24 use Instagram, so the Instagram social network analysis is important for understanding young people’s expressions in the context of healthy food. This study aims to identify the main topic associated with healthy food on the Instagram social network via hashtag and community analysis based on 2,045,653 messages created by 427,936 individual users. The results show that users most associate Healthy food with healthy lifestyle, fitness, weight loss and diet. In terms of food, these are foods that are Vegan, Homemade, Clean and Plant-based. Given that young people change their behavior in relation to people’s behavior on social networks, it is possible to use this data to predict their future association with healthy food characteristics. 相似文献